Certain stators for use in rotary machines such as electric motors or the like are made up of a plurality of separate cores, each comprising an arcuate yoke and a pole extending radially inward from the yoke, with a coil wound around the pole.
As disclosed in Japanese Patent No. 4073705, the present applicant has proposed a stator structure, which is produced by winding coils around the insulators of a plurality of separate cores, coupling the cores together and placing the separate cores in a case, and then filling junctions of the coils with a sealant such as a resin or the like and curing the sealant, thereby insulating the junctions.
Generally, the sealant often is made of a thermosetting resin that cures when heated. For curing the sealant in the stator, it has been the practice in the art to place the stator in a heating furnace to heat the stator, or to heat the stator with a heater that is positioned around the stator.
Since the sealant fills up a predetermined volume in the stator, it takes some time for heat to be transferred into the sealant from the surface thereof, with the result that the process of heating the sealant is time-consuming.
As disclosed in Japanese Laid-Open Patent Publication No. 2006-158094, for example, there has been proposed a technical concept for quickly heating a sealant in a stator, so as to cure the sealant in a short time using an external heating mechanism, which heats the sealant from outside of the stator, and a coil energizing mechanism that energizes the coil, which has been insulated by the sealant, in order to heat the sealant.